Brief summaries of tropical Atlantic activity tailored to the general public, coastal residents, and weather enthusiasts. I have been sending out these updates since 1996, and appreciate everyone's continued interest!

28 October 2015

Villa Vizcaya was built in 1914-1922 by James Deering. James was the son of William Deering, of Deering Harvester Company fame in the late 1800s. James joined the company when he was 21, and when he was 43, J.P. Morgan facilitated a merger with McCormick Reaper Company to form International Harvester, which quickly became the largest agricultural equipment manufacturer in the country.

James lived in Chicago, and wanted a winter house in south Florida. The pristine tropical coastline of Biscayne Bay near Miami was his chosen location (area map) for an immense 180-acre estate featuring manicured gardens, statues, and a mansion built in the Mediterranean Revival style.

Aerial view of the mansion, gardens, and stone barge in the bay entrance. (Google Earth)

James died in 1925 at age 66, and just one year later, the Great Miami Hurricane of 1926 severely damaged the property. Efforts to restore it were set back again by the Labor Day Hurricane of 1935. In the 1950s, James' heirs gifted the estate to Dade County, and it finally re-opened as Vizcaya Museum & Gardens for the public to experience and enjoy. In 1979, it was added to the National Register of Historic Places, and remains a beautiful public museum today (Vizcaya Museum & Gardens website) despite subsequent destructive hurricanes such as Andrew in 1992 and Wilma in 2005.

One thing James couldn't have anticipated 100 years ago was that the spectacular bay-front location would be endangered by the bay itself. Archeological work being conducted in downtown Miami by Robert Carr and colleagues recently "provided proof that sea level in the area had risen more than a foot in the last century" (Miami Herald article), and my own work with tide gauge data from nearby Virginia Key suggests that the sea level has risen nearly 4 inches in just the past 20 years, and that the rate of sea level rise is accelerating (RSMAS blog post).

So, I wanted to compare some photographs of the estate taken nearly 100 years ago to some taken during a "king tide" on October 28, 2015 from nearly the same vantage points. With assistance from Remko Jansonius, Nydia Perez, and Emily Gibson at Vizcaya's Collections and Curatorial Division, the following comparisons offer some perspective on the rising seas that will threaten this unique and historic gem in the coming years and decades.

Looking toward the north boat landing from the east entrance in January 1917 (top) and October 2015 (bottom). Top photo courtesy of the Construction Photograph Albums, Vizcaya Museum & Gardens. Bottom photo by Brian McNoldy.

Bridge to the north landing in 1917 (top, with gondolas) and October 2015 (bottom). Top photo courtesy of the Arva Moore Parks Vizcaya Photograph Collection, Vizcaya Museum & Gardens. Bottom photo by Brian McNoldy.

Bayfront view of Vizcaya from the north landing in 1917 (top) and
October 2015 (bottom). Top photo courtesy of the Construction
Photograph Albums, Vizcaya Museum & Gardens. Bottom photo by Brian
McNoldy.

For the next two photo comparisons, we fast-forward by 30-35 years to the early 1950s.

Bayfront view of Vizcaya from the north landing in 1950 (top) and October 2015 (bottom). Top photo detail courtesy of the Richard B. Hoit Photograph Collection, Vizcaya Museum & Gardens. Bottom photo by Brian McNoldy.

Although the photos from 2015 were taken during a very high "king tide",
that water level will soon enough be the new average, and then
eventually the new low tide. Sea level rise is happening, and will
continue to happen at even greater rates than we've ever measured. The
last 4 inches of sea level rise took 20 years to occur, but the next 4
inches may only take another 10 years or less!

Some additional photos from the October 28, 2015 "king tide" are provided here without comparison, but set a benchmark for the next generation of Vizcaya photographers...

Gazebo on the south side of the bayfront entrance. Photo by Brian McNoldy.

Only a few steps still remain above water on the bayfront entrance. Photo by Brian McNoldy.

Close-up of the stone barge, which appears to be two separate features. Photo by Brian McNoldy.

08 October 2015

Through October 8, the Atlantic has had 10 named storms, 3 hurricanes, and 2 of those became major hurricanes (Category 3+). The strongest by far was Joaquin, the only depression to not become a tropical storm was TD9, and the shortest-lived storm was Bill.

The final advisory was just written on Joaquin last night as it transitioned to an extratropical cyclone, so I'll go over its fairly unique evolution. Joaquin's origins could be traced all the way back to around September 17-18 as an upper-level low pressure system. While tropical development from upper-level "cold core" lows is not unheard of, it is rare for storms of that pedigree to become nearly Category 5 hurricanes. Here is a quick timeline as a recap:

Water vapor images at select milestones in Joaquin's lifecycle leading up to its peak intensity.

Joaquin was the strongest hurricane in the Atlantic since Igor in 2010. It was the first major hurricane to impact the Bahamas since Irene 2011. It maintained hurricane intensity up to 40.5°N (same latitude as Long Island, NY). In terms of Accumulated Cyclone Energy, or ACE, Joaquin racked up the same amount as all nine previous named storms combined! That brings 2015 up to approximately 65% of an average season by this date... so still decidedly "quiet" overall.

Even in distant 'model-land', the Atlantic looks quiet, and with a very strong El Nino in high gear in the central and eastern Pacific Ocean, tropical Atlantic activity should remain suppressed for the rest of the season. However, suppressed does not necessarily mean dead. October is historically still a month when extremely powerful hurricanes have formed and some of those made landfall. As Joaquin proved, we can still get very intense storms even though the overall seasonal activity is below average.

03 October 2015

Enhanced infrared satellite image of Joaquin and the U.S. east coast on Saturday morning.

Joaquin has devastated parts of the central Bahamas with nearly 2 feet of rain, destructive storm surge, tropical storm force winds for 3 days, and hurricane-force winds for 1.5 days. It will begin to clear up there today, so I'm sure we will start seeing more photos and videos of the aftermath. The anticipated turn to the north happened on Thursday night, and a turn more to the northeast occurred later Friday. The track history, as well as the current NHC forecast, is shown here:

The NHC forecast with the cone of uncertainty included is also shown for reference... note that Bermuda is now under a hurricane watch and a tropical storm warning. Although the cone is exactly the same size it has been for every storm all season, the current model guidance consensus makes this forecast much more confident than it previously was. A fixed-size cone is not capable of illustrating the evolving forecast confidence (see "Why the forecast cone of uncertainty is inadequate for Hurricane Joaquin").

Joaquin is now a Category 3 storm with maximum sustained winds of 125 mph, with a possibility of some strengthening today. It will then weaken gradually over the coming days as it encounters higher shear and cooler water. By the end of the week it is expected to transition to a strong extratropical cyclone.

Of course, the main event which has always been part of the forecast is the enormous rainfall totals along the U.S. east coast. An endless feed of deep tropical moisture from Hurricane Joaquin is streaming into the Carolinas and mid-Atlantic states, and won't be stopping anytime soon.

South Carolina has been the bullseye for incredible rains, which isn't surprising when you see the graphic above showing the moisture plume persistently centered on that state. The forecast through the end of the weekend is not good either... the flooding that is already happening will get much worse. Locations from South Carolina up to Maine are also experiencing coastal flooding due to onshore winds, but that is being caused by a mid-latitude storm system, not Joaquin.

The U.S. "dodged a bullet" with this storm. If a major hurricane had stalled over south Florida for 3 days, it's hard to even imagine the outcome. Or if it followed Sandy's path from three years ago, etc, etc. The prospect of a U.S. landfall was never presented as a certainty by anyone (I hope). There were times when the majority of model guidance as well as NHC indicated that the center could turn back west and hit the coast, but that should not be interpreted to mean that it was a sure thing. Times like this are when scientists and forecasters hope to educate the public more about probability and uncertainty, and that a single forecast is not always enough. Nature is just sometimes inherently less predictable than other times, the hard part is communicating that to everyone.

With Joaquin, this season has now had 10 named storms, 3 hurricanes, and 2 major hurricanes (Cat3+). The average for this date, using a 1981-2010 climatology, is 9 named storms, 4 hurricanes, and 2 major hurricanes. However, in terms of Accumulated Cyclone Energy, or ACE, this season is running at just a little over 50% of average for this date because most of the storms that formed were so short-lived.

01 October 2015

Another post today... it was just too much to cram into one. This covers an extremely important and timely topic: uncertainty in forecasts. In particular, the shortcomings of NHC's "cone of uncertainty".

Author: Brian McNoldy,Senior Research Associate at University of Miami's Rosenstiel School of Marine and Atmospheric Science

"In the eye of a hurricane, you learn things other than of a scientific nature. You feel the puniness of man and his works. If a true definition of humility is ever written, it might well be written in the eye of a hurricane." -Edward Murrow, reporting on Hurricane Edna 1954